1. **Problem Statement:** We have a horizontal HEB 120 beam supported by two vertical flat steel bars (A and B) each 120 mm wide and 8 mm thick. The beam length is 2.2 meters and the distance between the vertical supports A and B is 1.8 meters. We want to sketch the system and calculate the forces acting on the beam in static equilibrium. 2. **Sketch:** Draw the horizontal beam with two vertical supports A and B underneath, spaced 1.8 meters apart. Label total beam length as 2.2 meters. 3. **Known parameters:** - Length between supports: $L = 1.8$ m - Total beam length: $L_{total} = 2.2$ m - Flat steel dimensions (for A and B): width $= 120$ mm $= 0.12$ m, thickness $= 8$ mm $= 0.008$ m 4. **Assumptions:** The beam is in static equilibrium, so the sum of forces and moments are zero. 5. **Forces on the beam:** - Let $F_A$ and $F_B$ be the vertical reaction forces at supports A and B. - The beam carries some distributed load or other loads not explicitly stated; if unknown, we can only analyze reactions based on external loading stated. If no other loads are given, the beam is considered simply supported and the forces can be reaction forces balancing external loads (like self-weight or applied loads). Since none are given, we'll denote an external load $W$ applied at some point. 6. **Calculations:** - Sum of vertical forces: $$F_A + F_B - W = 0$$ - Sum of moments about A: $$F_B \times 1.8 - W \times d = 0$$ where $d$ is the distance from A to the point of load $W$. Without specified $W$ or load position, the problem is underspecified. Assume load $W$ acts at the center of the span at $0.9$ m from A. Then moments about A: $$F_B \times 1.8 - W \times 0.9 = 0 \Rightarrow F_B = \frac{W \times 0.9}{1.8} = \frac{W}{2}$$ Sum of vertical forces: $$F_A + F_B = W \Rightarrow F_A + \frac{W}{2} = W \Rightarrow F_A = \frac{W}{2}$$ 7. **Final answer:** Reactions at supports A and B are equal and each supports half the total load $$\boxed{F_A = F_B = \frac{W}{2}}$$ You should measure or specify the actual load $W$ on the beam to find numerical values for $F_A$ and $F_B$.